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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
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The KSFM Journal of Fluid Machinery
Journal Basic Information
Journal DOI :
Korean Fluid Machinery Association
Editor in Chief :
Volume & Issues
Volume 17, Issue 6 - Dec 2014
Volume 17, Issue 5 - Oct 2014
Volume 17, Issue 4 - Aug 2014
Volume 17, Issue 3 - Jun 2014
Volume 17, Issue 2 - Apr 2014
Volume 17, Issue 1 - Feb 2014
Selecting the target year
An Analytical Study on Evaluation of Opening Performance of Steam Safety Valve for Nuclear Power Plant
Sohn, Sangho ;
The KSFM Journal of Fluid Machinery, volume 17, issue 1, 2014, Pages 5~11
DOI : 10.5293/kfma.2014.17.1.005
The purpose of this paper is to investigate an analytical approach for opening performance evaluation of the nuclear pressure safety valve based on standard codes such as ASME or KEPIC. It is well-known that safety valve is considered as one of pressure relief valves for protecting a boiler or pressure vessel from exceeding the maximum allowable working pressure. When pressure in a container reaches its set pressure, the safety valve commences discharging the internal fluid by a sudden opening called as popping. Safety valve is usually evaluated by set pressure, full open, blow-down, leakage and flow capacity. The test procedure and technical requirement for performance evaluation is described in international code of ASME code such as BPVC. The opening characteristics of steam safety valve can be analyzed by computational fluid dynamics (CFD) and steam shaft dynamics. First, the flow analysis along opening process is simulated by running the CFD models of the ten types of opening steps from 0 to 100%. As a analysis result, the various CFD outputs of flow pattern, pressure, forces on the disc and mass flow at each simulation step is demonstrated. The lift force is calculated by using the forces applied on disc from static pressure and secondary flow. And, the effect of huddle chamber or control chamber is studied by dynamic analysis based on CFD simulation results such as lift force. As a result, dynamics analysis shows opening features according to the sizes of control chamber.
A Study on the Organic Rankine Cycle for the Fluctuating Heat Source
Cho, Soo-Yong ; Cho, Chong-Hyun ;
The KSFM Journal of Fluid Machinery, volume 17, issue 1, 2014, Pages 12~21
DOI : 10.5293/kfma.2014.17.1.012
An organic Rankine cycle was analyzed to work at the optimal operating point when the heat source is fluctuated. R245fa was adopted as a working fluid, and an axial-type turbine as expander on the cycle was designed to convert the heat energy to the electricity since the turbo-type expander works at off-design points better than the positive displacement-type expander. A supersonic nozzle was designed to increase the spouting velocity because a higher spouting velocity can produce more output power. They were designed by the method of characteristics for the operating fluid of R245fa. Three different cases, such as various spouting velocities, various inlet total temperatures, and various nozzle numbers, were studied. From these results, an optimal operating cycle can be designed with the organic Rankine cycle when the available heat source as renewable energy is low-grade temperature and fluctuated.
Performance Evaluation on Water-mist Extinguishing System of Railway Vehicles
Park, Won-Hee ; Eum, Pu-Reun-Byul ; Yoon, Kyung-Beom ; Lee, Duck-Hee ;
The KSFM Journal of Fluid Machinery, volume 17, issue 1, 2014, Pages 22~27
DOI : 10.5293/kfma.2014.17.1.022
The test system for the performance of the water-mist extinguishing system in the railway vehicle is equipped and the details of the system are introduced. The three scenarios using different fire sources and performance criteria for the water-mist systems on railway vehicles are also introduced. Three different type of the nozzle at same operating pressure are evaluated. Amount of water-mist distribution is measured by many baskets on the bottom of the test room. Temperature on the ceil and the tree of the test room is measured during the tests that are used for the judgement of the performance on the water-mist extinguishing system.
Performance Characteristics of the Double-Inlet Centrifugal Blower according to the Shape of an Impeller
Lee, Jong-Sung ; Jang, Choon-Man ;
The KSFM Journal of Fluid Machinery, volume 17, issue 1, 2014, Pages 28~34
DOI : 10.5293/kfma.2014.17.1.028
This paper presents the performance enhancement of a double-inlet centrifugal blower by the shape optimization of an impeller. Two design variables, a number of blade and a length of chord, are introduced, and analyzed by a response surface method. Three-dimensional compressible Navier-Stokes equations are used to analyze the blower performance and the internal flow of the blower. Throughout the numerical simulation of the blower, blower efficiency can be increased by reducing separation flow generating from the blade leading edge of a blade pressure surface. It is noted that recirculation flow observed inside the blade passage induces low velocity region, thus increases pressure loss. Efficiency and pressure of the optimum blower are successfully increased up to 3% and 3.9% compared to those of reference blower at the design flow condition, respectively. Detailed flow field inside the blower is also analyzed and compared.
Development of An Integrated Optimal Design Program for Design of A High-Efficiency Low-Noise Regenerative Fan
Heo, Man-Woong ; Kim, Jin-Hyuk ; Seo, Tae-Wan ; Koo, Gyoung-Wan ; Lee, Chung-Suk ; Kim, Kwang-Young ;
The KSFM Journal of Fluid Machinery, volume 17, issue 1, 2014, Pages 35~40
DOI : 10.5293/kfma.2014.17.1.035
A multi-objective optimization of a regenerative fan for enhancing the aerodynamic and aeroacoustic performance was carried out using an integrated fan design system, namely, Total FAN-Regen
. The Total FAN-Regen
was developed for non-specialists to carry out a series of design process, viz., computational preliminary design, three-dimensional aerodynamic and aeroacoustic analyses, and design optimization, for a regenerative fan. An aerodynamic analysis of the regenerative fan was conducted by solving three-dimensional Reynolds-averaged Navier-Stokes equations using the shear stress transport turbulence model. And, an aeroacoustic analysis of the regenerative fan was implemented in a finite/infinite element method by solving the variational formulation of Lighthill's analogy based on the results of the unsteady flow analysis. An optimum shape obtained by Total FAN-Regen
shows the enhanced efficiency and decreased sound pressure level as much as 1.5 % and 20.0 dB, respectively, compared to those of the reference design. The performance test was carried out for an optimized regenerative fan to validate the performance of the numerically predicted optimal design.
Effect of the Configurations of Coolant Flow Passage on the Thermal-Flow Characteristics of Screw Compressor
Cho, Sung-Wook ; Seo, Hyeon-Seok ; Shon, Kil-Won ; Kim, Youn-Jea ;
The KSFM Journal of Fluid Machinery, volume 17, issue 1, 2014, Pages 41~46
DOI : 10.5293/kfma.2014.17.1.041
The thermal-flow characteristics of screw compressor were numerically investigated with various geometrical configurations of its coolant flow passage applied to the separate block for enhancing the heat transfer performance of it. The length ratio(
=4.8, 5.6, 6.4) and thickness ratio(t/D=0.2, 0.4, 0.6) of the separate block in the flow passage of the water jacket were adopted to design parameters. Results showed that the pressure drop and heat transfer were increased as the length of separate block increases due to the flow separation and centrifugal force. The results were graphically depicted with various flow and geometrical conditions.
Design and Performance Evaluation of a 10kW Scale Counter-Rotating Tidal Turbine
Hoang, Anh Dung ; Yang, Chang-Jo ;
The KSFM Journal of Fluid Machinery, volume 17, issue 1, 2014, Pages 47~53
DOI : 10.5293/kfma.2014.17.1.047
This paper aims to present the design and performance evaluation of a counter-rotating tidal turbine using CFD and to compare its performance with single rotor. The device scale is 10kW and the rotating part consists of two rotors which rotate in opposite direction. Compared with conventional single rotor, the counter-rotating system shows higher power efficiency at high stream velocity but lower efficiency at low stream velocity. The added counter-rotated rotor together helps improve the energy absorption capacity but has influence on the upstream rotor that reduces its performance. In terms of power capture, the designed counter-rotating tidal turbine is more advantageous in high speed tidal condition.